1. Field of the Invention
This invention relates to front door weather strips, and more particularly to a front door weather strip which comprises a base section which is mounted on the periphery of a front door of a vehicle, and a hollow sealing section which is extended from the base section. The front door weather strip is annular as a whole.
2. Description of the Related Art
Heretofore, a front door weather strip is mounted on the periphery of a front door of a vehicle to seal the gap between the front door and the vehicle body. In the weather strip of this type, its mainly substantially straight part is formed by extrusion molding, and its corner part small in the radius of curvature is formed by using a mold (hereinafter referred to as "mold molding", when applicable) (cf. Japanese Utility Model Publication No. Hei. 1-168346, Japanese Utility Model Publication No. Hei. 2-26934, or the like). The weather strip fundamentally comprises a base section which is mounted on the periphery of a front door, and a hollow sealing section which is extended from the base section, and is formed, for instance, with EPDM solid rubber or sponge rubber.
FIG. 8 is a side view of a conventional front door weather strip. As shown in FIG. 8, the weather strip 70 comprises three extrusion molding sections (a first extrusion molding section 71, a second extrusion molding section 72, and a third extrusion molding section 73); and three mold molding sections (a first mold molding section 74, a second mold molding section 75, and a third mold molding section 76) which connect the ends of those three extrusion molding sections and are dotted in FIG. 8. The reason why the mold molding sections 74 through 76 are provided is as follows: If the whole weather strip is formed by extrusion molding suffers from the following trouble: In the case where the corner is small in the radius of curvature, and it is desired to curve the extrusion molding section along the corner section, the corner section is deformed in such a manner that the hollow sealing section collapses; that is, a predetermined sealing force cannot be obtained. The extrusion molding sections are greatly different in sectional configuration from each other, the mold molding section is provided at the junction of the extrusion molding sections.
FIG. 9 is a sectional view taken along line IX--IX in FIG. 8. FIG. 10 is a sectional view taken along line X--X in FIG. 8. FIG. 11 is a sectional view taken along line XI--XI in FIG. 8. As shown in those figures, the first extrusion molding section 71 corresponding to the region from the upper section to the front side section of the front door, as was described before, fundamentally comprises a base section 77, and a hollow sealing section 78 which is integral with an outwardly protruded seal lip 79, and a rear surface seal 80. On the other hand, the second extrusion molding section 72 corresponding to the front side section of the front door has no seal lip 79. Also, in the second mold molding section 75, the seal lip 79 is gradually changed in length, and the seal lip 79 is eliminated at the junction of the second extrusion molding section 72 and the second mold molding section 75.
The above-described weather strip 70 has the following problems: The front door weather strip needs three extrusion molding sections 71, 72 and 73, and three mold molding sections 74, 75 and 76. Therefore, those sections 71 through 76 must be formed in different manufacturing steps, and accordingly the number of manufacturing steps is considerably large; that is, the manufacturing work is low in efficiency, and the manufacturing cost is large.
On the other hand, a method may be employed in which the second mold molding section 75 and the third mold molding section 76, which are relatively larger in the radius of curvature than the first mold molding section 76, are eliminated, and the part corresponding to the upper section, the front side section, lower section and the rear side section of the front door is provided as one extrusion molding section. However, in this case, as was described above, the hollow sealing section of the part corresponding to the corner section between the front side section and the lower section of the front door is deformed in such a manner that the hollow sealing section collapses; that is, the predetermined sealing force cannot be obtained.